Various methods for infusing vegetables with sugar and other infusion syrups are well-known. Early methods of infusing vegetables included simply storing the vegetables in a sugar/water solution, within a container. When the container was later opened, it was observed that the water had been extracted from the vegetables and sugar had been infused into the vegetables. These batch processes were accomplished on a larger scale by charging several hundred gallons of a high Brix syrup (45 degrees to 67 degrees) to a large tank, circulating the syrup through the tank, adding more sugar to the syrup, heating the syrup to a temperature from about 100 degrees F. to about 200 degrees F., then immersing the vegetables therein. Typically, the syrup was circulated over and through the bed of vegetables, and the temperature of the system was lowered to an infusion temperature between about 60 degrees F. and about 110 degrees F., depending upon the type of vegetables being infused. This combination of vegetables and syrup was maintained within the tank for a period of time ranging from about 3 to about 12 hours. At the end of this time period, the concentration of sugar in the syrup and the vegetables would be nearly equal, i.e., within about 5 degrees to about 15 degrees Brix of each other. Thus, the vegetables would have been infused with sugar to a level of perhaps 40 degrees to about 52 degrees Brix, depending upon the type of vegetables being infused. After the infused vegetables were removed from the infusion apparatus, the spent infusion syrup was reconcentrated by the evaporation of water therefrom and recycled back to the tank to begin the batch process again. Batch infusion processes are disclosed in U.S. Pat. No. 5,000,972 to Nafisi-Movaghar, U.S. Pat. No. 4,713,252 to Ismail, U.S. Pat. No. 4,551,348 to O'Mahony et al, U.S. Pat. No. 4,542,033 to Agarwala, U.S. Pat. No. 4,626,434 to O'Mahony et al, and U.S. Pat. No. 4,256,772 to Shanbhag et al.
Recently, continuous processes for infusing vegetables have been developed. U.S. Pat. No. 5,320,861 to Mantius et al discloses a process for infusing produce with sugar by a continuous process.
Carrots are a particularly desirable vegetable for infusing. Carrots are an excellent source of beta carotene, and are also high in dietary fiber. The bright orange color, sweet taste, and suitability as a snack, salad component, canned vegetable, and food ingredient for soups, cereals, and bakery products, make carrots a prime choice for infusion processing, to produce a value added vegetable product.
It is noted that other methods for preserving carrots, i.e., dehydration, where high heat levels are applied directly to the vegetable, can adversely affect the color and texture of the resultant dried carrots.
It would be desirable to develop an improved process for the infusion-drying of carrots, said process resulting in a product having an extended shelf life, a bright orange carrot-like color, and the taste of fresh carrots.